Citrus aurantifolia is part of the Rutaceae family and belongs to the genus Citrus. It is widely used in food, the chemical industry, and pharmaceuticals because it has a unique flavor and odor. It is nutrient-rich and is beneficial as an antibacterial, anticancer, antioxidant, anti-inflammatory, and insecticide. Secondary metabolites present in C. aurantifolia are what give rise to biological action. Flavonoids, terpenoids, phenolics, limonoids, alkaloids, and essential oils are among the secondary metabolites/phytochemicals discovered in C. aurantifolia. Every portion of the plant’s C. aurantifolia has a different composition of secondary metabolites. Environmental conditions such as light and temperature affect the oxidative stability of the secondary metabolites from C. aurantifolia. The oxidative stability has been increased by using microencapsulation. The advantages of microencapsulation are control of the release, solubilization, and protection of the bioactive component. Therefore, the chemical makeup and biological functions of the various plant components of C. aurantifolia must be investigated. The aim of this review is to discuss the bioactive components of C. aurantifolia such as essential oils, flavonoids, terpenoids, phenolic, limonoids, and alkaloids obtained from different parts of the plants and their biological activities such as being antibacterial, antioxidant, anticancer, an insecticide, and anti-inflammatory. In addition, various extraction techniques of the compounds out of different parts of the plant matrix as well as the microencapsulation of the bioactive components in food are also provided.

Adsorption kinetics is part of adsorption and discusses the adsorption rate of an adsorbent on the adsorbate. Adsorption kinetics has an equation to determine the rate constant of adsorption, namely the pseudo-first order and pseudo-second order. In this study, methylene blue was adsorbed using a C-4-hydroxy-3-methoxyphenylcalix[4]resorcinarene (CHMFKR) adsorbent. The aim of this study to determine the effect of process parameters (concentration, pH, and processing time) on the process adsorption, with the Langmuir and Freundlich adsorption isotherm model approach, and to determine the adsorption kinetics of methylene blue with CHMFKR. Ten mL of methylene blue solution with various concentrations of 5, 6, 8, 10, and 11 ppm with a solution pH of 7 was added to as much as 0.001 gram of CHMFKR adsorbent and stirred at 600 rpm for 40 minutes. The solution was measured, and its absorbance was measured using the UV-Vis Spectrophotometer. The results show that the adsorption kinetics follow pseudo second order with an adsorption rate of 0.7217 ± 0.4 g/mg.s. The adsorption isotherm follows the Langmuir equation, and the maximum adsorption amount is 114.94 ± 2.04 mg/g.

Hazmat is one of the personal protective equipment (PPE) used by healthcare professionals to combat infections such as Ebola, SARS, MERS, and the current prevalence of COVID-19. There are several things to consider when making this hazmat clothing. That is a type of hazmat material, standardization, and ease of use. Adding an outer layer of hazmat clothing containing betel leaf (Piper Betle. L) extract in an antibacterial and antiviral spray is expected to increase the safety of healthcare professionals and enhance protection from bacteria/viruses. In this course, we apply Research and Development (R&D) methods. The research steps were carried out experimentally in the laboratory by applying a betel leaf (Piper Betle. L) extract in a spray formulation. Spray formulation prepared at a leaf extract concentration; of 0%, 2.5%, 5%, and 7.5% and sprayed on a hazmat suit. Then the hazmat is used by health workers and tested for the number of bacteria in the laboratory. Based on the research, a spray with 7.5% leaf extract concentration showed maximum antibacterial activity in 16 bacterial colonies before the test and one colony after the test.